【medical-news】窒息是如何引起中风的？

WASHINGTON (Reuters) - A dangerous type of snoring known as sleep apnea can cause stroke by decreasing blood flow, raising blood pressure and harming the brain's ability to modulate these changes, researchers reported on Tuesday.

The study may help explain why people with sleep apnea are more likely to have strokes and to die in their sleep, the team led by Vahid Mohsenin of Yale University in Connecticut said.

An estimated 18 million Americans have sleep apnea, which is characterized by repeated episodes in which someone who is sleeping stops breathing.

"Three years ago we showed that patients with sleep apnea ... they die or have strokes three times more than people with a comparable age or risk factors without sleep apnea," Mohsenin said in a telephone interview.

"We asked the question of why they have a higher risk for stroke."

Writing in the Journal of Applied Physiology, Mohsenin and colleagues said they tested 48 middle-aged men and women, 22 of whom had sleep apnea but who were otherwise healthy. They checked blood pressure and used ultrasound to monitor blood flow in the brain.

They had the volunteers do a blood pressure test in which they squatted and then stood suddenly.

"We found that patients with sleep apnea had difficulty compensating for the change in blood pressure," Mohsenin said. "They actually had decreased blood flow to brain."

He said this showed the damage caused by sleep apnea continues throughout the day.

"When you are up and around and experience changes in your blood pressure, or during the night when you have fluctuations in blood pressure due to apnea, they have a hard time compensating for that," Mohsenin said.

"It is a carryover effect."

Now, Mohsenin said, his team will test whether statin drugs, known to reduce inflammation, can restore the lost brain function in sleep apnea sufferers.

The patients will also later be treated using airway pressurization masks, or CPAP.

"The important thing is to recognize sleep apnea early on so there won't be any significant damage to the brain," he said.

WASHINGTON (Reuters) - A dangerous type of snoring known as sleep apnea can cause stroke by decreasing blood flow, raising blood pressure and harming the brain's ability to modulate these changes, researchers reported on Tuesday.华盛顿（路透社）-研究者在星期二报道：一种名为睡眠呼吸暂停综合症的危险的鼾症可以通过减慢血流、增加血压并损害脑调节这些变化的功能从而引起中风。The study may help explain why people with sleep apnea are more likely to have strokes and to die in their sleep, the team led by Vahid Mohsenin of Yale University in Connecticut said.由康涅狄格州耶鲁大学的Vahid Mohsenin领导的研究小组认为：这项研究能够解释为什么睡眠呼吸暂停综合症的人会更容易罹患中风，并在睡眠中死亡。An estimated 18 million Americans have sleep apnea, which is characterized by repeated episodes in which someone who is sleeping stops breathing.据估计，美国有1800万人患有睡眠呼吸暂停综合症，这种疾病以睡眠中反复发生呼吸暂停为特征。"Three years ago we showed that patients with sleep apnea ... they die or have strokes three times more than people with a comparable age or risk factors without sleep apnea," Mohsenin said in a telephone interview.Mohsenin在一个电话会议中说：“三年前我们的研究结果显示患有睡眠呼吸暂停综合症的患者较相同年龄或没有睡眠呼吸暂停综合症危险因素的患者相比，死亡或发生中风的风险要大三倍”。"We asked the question of why they have a higher risk for stroke."“我们不清楚为什么他们发生中风的风险更高”。Writing in the Journal of Applied Physiology, Mohsenin and colleagues said they tested 48 middle-aged men and women, 22 of whom had sleep apnea but who were otherwise healthy. They checked blood pressure and used ultrasound to monitor blood flow in the brain.